Charlotte absolutely trounced Rhea 3 years ago during their feud. It makes sense that they would settle the score, but Charlotte isn't exactly the most charitable wrestler.
Like, the issue wasn't so much that Charlotte went over. Rhea became the NXT champ dethroning Shayna Baszler in what was essentially a reign of terror. People cheered. Her first big feud was against Charlotte and not only BIG CHAR went to NXT to take that belt, she not even got pinned for it, Rhea was!
Triple H, at the time, said "oh, it will all make sense in 3 to 4 months I swear". More like three to 4 years!